The extent of competition among industrial firms has been the subject of scores of empirical investigations. Various techniques have been applied to determine which industry or firm characteristics are associated with socially desirable business conduct or performance. These methods have traditionally included intensive studies of particular industries and, more recently, several varieties of econometric tests. A third, and less well known, general type of quantitative studies of industrial competition are known as 11mobility11 or "turnover" studies. The principal purpose of this paper is to review several of the more recent studies of this type and to apply the technique to the U.S. food manufacturing sector over the quarter century 1950-1975.